import java.util.TreeMap;

public class MapSum {
    private class Node{
        private int value;
        private TreeMap<Character, Node> next;

        public Node(int value){
            this.value = value;
            this.next = new TreeMap<>();
        }
        public Node(){
            this(0);
        }
    }

    private Node root;
    public MapSum(){
        this.root = new Node();
    }

    public void insert(String word,int val){
        Node cur = root;
        for(int i=0;i<word.length();i++){
            char c = word.charAt(i);
            if(cur.next.get(c) == null){
                cur.next.put(c,new Node());
            }
            cur = cur.next.get(c);
        }
        cur.value = val;
    }

    /***
     * 获取以prefix为前缀的所有单词的value和
     * @param prefix
     * @return
     */
    public int sum(String prefix){
        Node cur = root;
        for(int i=0;i<prefix.length();i++){
            char c = prefix.charAt(i);
            if(cur.next.get(c) == null){
                //不存在此前缀的单词
                return 0;
            }
            cur = cur.next.get(c);
        }
        return sum(cur);
    }

    private int sum(Node node){
        int res = node.value;
        for(char c : node.next.keySet()){
            res += sum(node.next.get(c));
        }
        return res;
    }
}
